Distribution of Telomeric Sequences (TTAGGG)n in Rearranged Chromosomes of Phyllotine Rodents (Cricetidae, Sigmodontinae)

C. LANZONE; LABARONI, C.A.; SUAREZ N; D. RODRÍGUEZ; HERRERA M; BOLZÁN A

CYTOGENETIC AND GENOME RESEARCH

KARGER

Lugar: Basel; Año: 2016 vol. 147 p. 247 - 252

1424-8581

Phyllotineare sigmodontine rodents endemic to South America with broad geneticvariability, being Robertsonian polymorphisms the most frequent. Moreover, thistaxon includes a species with multiple sex chromosomes, which is infrequent inmammals. However, molecular cytogenetic techniques were never applied tophyllotines to study its karyotypic evolution. We study the chromosome of four phyllotinespecies using FISH with a pantelomeric probe (TTAGGG)n. Graomysgriseoflavus, Eligmodontia puerulusand E. morgani are polymorphic for Robertsoniantranslocations; whereas Salinomysdelicatus posses XX/XY1Y2 sex chromosomes. Telomeric signalswere detected at both ends of all chromosomes of studied species. In S. delicatus interstitial telomericsequences (ITS) were observed in the three major chromosome pairs, which areequidistant from one of the telomeres in these chromosomes. These results suggest that ITS are important in thereshuffling of the highly derived karyotype of S. delicatus. Considering the phylogeny of phyllotines, the Robertsonianrearrangements of G. griseoflavus, E. puerulus and E. morganipossibly represent chromosome fusions which have occurred independently. The pericentromericregions of the biarmed chromosomes of these species do not contain thetelomeric sequences characteristic of strict fusions of recent origin, suggestinga common pattern of telomeric repeats loss during the chromosomal evolutionof these rodents.